Publication Date:
2019-07-17
Description:
Over the last four decades, different hypotheses
of Ca2+ and dissolved inorganic carbon transport to
the intracellular site of calcite precipitation have
been put forth for Emiliania huxleyi (Lohmann) Hay
& Mohler. The objective of this study was to assess
these hypotheses by means of mathematical models.
It is shown that a vesicle-based Ca2+ transport would
require very high intravesicular Ca2+ concentrations,
high vesicle fusion frequencies as well as a fast
membrane recycling inside the cell. Furthermore, a
kinetic model for the calcification compartment is
presented that describes the internal chemical
environment in terms of carbonate chemistry
including calcite precipitation. Substrates for calcite
precipitation are transported with different
stoichiometries across the compartment membrane.
As a result, the carbonate chemistry inside the
compartment changes and hence influences the
calcification rate. Moreover, the effect of carbonic
anhydrase (CA) activity within the compartment is
analyzed. One very promising model version is
based on a Ca2+/H+ antiport, CO2 diffusion, and a
CA inside the calcification compartment. Another
promising model version is based on an import of
Ca2+ and HCOÀ and an export of H+.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
Format:
application/pdf
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